Above: A Denver crime-scene investigator walks past a dowel rod marking the entry point of a bullet that pierced the wall and killed an 11-year-old girl and her 48-year-old aunt Tuesday morning. Left: Police officers search for slugs on a hillside outside the house where the two victims were shot. A second bullet was found, but no suspects have been identified.

Angelica Martinez and Becky Yanez were killed early New Year's morning when a shot was fired into the Denver home where they were celebrating.

Police detectives have arrested a 25-year-old Denver man in connection with the shooting deaths of a 48-year-old woman and her 11-year-old niece early Tuesday morning.

Pedro Cortez is being held for investigation of two counts of first-degree murder, police spokesman Sonny Jackson said.

Jackson would not discuss details of the case Tuesday night.

“I can say that it was amazing police work, like looking for a needle in a haystack,” Jackson said. “Frankly, I’m amazed we have a suspect in custody tonight.”

Investigators said they believe a single bullet fired from a high-powered rifle as part of a holiday celebration accidentally struck and killed Angelica Martinez, 11, and her aunt, identified by family members as Rebecca “Becky” Yanez, 48, of Fort Collins. They were attending a party at a relative’s home at 4708 W. 11th Ave.

At about 12:25 a.m., the bullet pierced the wall of the house, ripped through Yanez’s head as she sat in a chair and then struck Angelica in the chest, Denver Police Chief Gerry Whitman said.

Yanez was visiting family with her 14-year-old daughter, Jeanette, when she was killed.

“She had a very big heart,” Jeanette Yanez said of her mother. “She would do anything for anybody. She didn’t deserve this.”

Before the arrest, investigators said they believed the shooting was a “tragic accident” and that the shot was fired across a gulch from a distance of up to 300 yards.

Police discovered a bullet on a hillside in Lakewood Gulch Park about 50 yards in front of the house. Whitman said detectives believe the bullet is related to the fatal shooting.

The deaths mark the second fatal New Year’s Day shooting in Denver in as many years. On Jan. 1, 2007, Denver Broncos cornerback Darrent Wil liams was shot and killed after leaving a nightclub in a limousine.

Friends and relatives of Yanez and Angelica said the pair were at a party attended by about a dozen people.

Yanez, who is separated from her husband and has a floral-arrangement business in Fort Collins, was pronounced dead at the scene, and Angelica was taken to a hospital, where she was pronounced dead, police said.

Investigators used lasers early Tuesday to trace the bullet’s trajectory, and officers scoured an area across the gulch from the home looking for evidence.

Gunshots widespread in city

Whitman said there were numerous reports of gunshots and fireworks across the city early Tuesday morning.

“It could be just a tragic accident — and something that reckless certainly is illegal,” he said before the arrest.

The bullet hole was about a foot above and to the right of a plastic snowman on the porch of the white, single-story house.

“It’s tough. We have two innocent people dead on a holiday,” Whitman said.

The house that was struck has a trampoline, a swing set and several toys in the backyard. Christmas decorations adorn the front porch. Across the street is Lakewood Gulch Park. The body of 3-year-old Neveah Gallegos was dumped in a garbage bag in a ravine in the park in September.

“We all just ducked and ran”

Angelica’s friend, Martin Vasquez, 11, said he and another friend went outside to watch and listen to New Year’s fireworks at midnight.

When the fireworks died down, they went back inside the house and were playing video games with Angelica in a bedroom.

Angelica giggled and teased Vasquez about his awkwardness while playing the “Guitar Hero” video game and then walked to the living room.

Then, Vasquez heard about five loud gunshots. Other neighbors said they heard three or four shots.

“We all just ducked and ran,” Vasquez said.

Moments later, he said, Vasquez saw Angelica lying on the floor with blood on her face.

Nobody inside the house saw the shooter, he said.

Whitman said police have no reason to believe that the family that lives in the home was targeted because of gang or other criminal activity.

Kirk Mitchell is a general assignment reporter at The Denver Post who focuses on criminal justice stories. He began working at the newspaper in 1998, after writing for newspapers in Mesa, Ariz., and Twin Falls, Idaho, and The Associated Press in Salt Lake City. Mitchell first started writing the Cold Case blog in Fall 2007, in part because Colorado has more than 1,400 unsolved homicides.

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